He criticized openness as a concept in and of itself, not some particular attribute of Android, so the extrapolation is not an extrapolation, it's stating the logical and immediate consequence of his argument. He DID argue that what makes it impossible to earn money as a developer is the platform being open. I pointed the PC as a painfully obvious counterexample. His tantrum^H^H^H^H^H^H^H argument is idiocy, and stating that it is idiocy, and therefore the person arguing that is an idiot, is not ad hominem, but a statement of fact.
He's an idiot. So are you. (In addition to being anonymous and a coward.)